Mine was a pre WW2 6X9 Super Ikonta, so it was a completely different camera.
I'm sure its a combination of model differences and evolution.
I took my camera apart last night. The above pictures were helpful. The two slotted screws under the top pate were rather stiff to turn at first, but eventually came out. I Also took out much of the gearing to be cleaned and relubed.
The Screws on the bottom were harder to access. Instead of the leatherette being attached directly to the base of the camera, as it is to the sides, there is a bottom plate, much like the top one, but it is held on with 9 screws under the leatherette. I used my fingernail to peel the leatherette away in little steps, that worked well. After finding and removing all 9 screws, the bottom plate comes off and revels the 2 screws holding the bottom of the folding assembly.
Before you can actually pull the assembly out you need to remove the shutter levers. There is chrome plated lever and cam that screw in with two screws on the bottom left of the camera body. Next you need to remove the lens and fold the bellows back into the body. The lever and cam now has room to lift vertical and can be turned out if the slot it sits in. Once that has been removed you can continue on to remove the assembly. The assembly was stuck in with time, and the top part sits behind the rangefinder optics. Wiggling and pulling from the bottom, the bottom slides out and the top comes out from behind the box in the body. The whole thing should come out at this point. The assembly won't stay closed until you unhook the two springs in the back.
The bellows is held in by the folding assembly and just falls out. Make sure to note the orientation that it came out, so you can put it back in, although I think it is symmetric and can be flipped 180 degrees with out issue. Mine had a few light seals in the back and seemed to be missing a few as well.
The bellows fabric is a laminate of leatherette, ribs and black fabric. The leatherette on the out side appears to be the light proof portion. The bellows is glued to two metal plates at either end.